We are online more than ever, glued to computers at work, and smartphones and tablets at home, during commutes and everywhere in between. But how are we filling up all that extra screen time other than checking social media, playing games and reading articles?

We're watching videos, preferably funny ones.

Since 2009, the percentage of adults watching or downloading online videos has gone up from 69% to 78%, according to new research from the Pew Internet & American Life Project. The most popular way of viewing clips is streaming them through video-sharing sites such as YouTube, followed by regular websites, apps and via social media. Thirty-six percent of people bother to download entire video files.

Comedy videos are hands down the most popular genre, holding on to the No. 1 spot from four years ago. Fifty-eight percent of adults are giggling along to comedy videos, and 56% are getting guidance from how-to videos. Music videos also have taken off in those four years, and now half of adults watch them.

Pornography was at the bottom of the list of video categories -- after sports and advertisements.Only 12% of people reported watching adult videos online. Twenty-five percent of men admitted to viewing adult content, while 8% of female respondents did.

Regular people are filming and uploading a large chunk of online videos.

In four years, the percentage of American adults posting videos online has shot up from 14% to 31%. The majority of people are uploading a video someone else created, but 18% of online adults shot and shared videos themselves.

The publicly shared moments are mostly mundane -- 58% of the shooters are uploading clips of people they know doing "everyday" things. The next most popular subject matter is people shooting themselves and their friends hamming it up for the camera for a laugh. Finally, 54% shared videos of events they attended, which may explain what the sea of people watching concerts through their smartphones instead of looking at the stage do with their videos.

Smartphones play a big role in the surge in amateur filmmakers. Anyone with a smartphone or tablet can capture spontaneous moments or whip up their own attempts at stardom. Forty percent of adults are recording video on their phones, and 41% are watching videos from the devices.

Not surprisingly, a bit of stardom is what many people are aiming for with their videos. More than a third of the people posting videos online hope one of their creations will go viral. Five percent of people posting videos regretted sharing something in the past.

Pew credits sharing sites such as YouTube and Vimeo as being the "main driving force" behind the video-watching trend. Back in 2006, 33% of people said they were using these types of sites. Now that number is 72%.

Apps such as Vine and other social media tools are becoming a popular way to share and consume videos directly from a phone.

The study was part of Pew's ongoing look at how Americans use the Internet. The phone survey of 1,003 American adults was conducted in July. The sampling error was plus or minus 3.6 percentage points.